1. Field of the Invention
This invention relates generally to ground proximity warning systems for aircraft, and more particularly to systems that monitor the altitude above ground and the closure rate of the aircraft to determine a dangerous flight condition.
2. Description Of The Prior Art
Ground proximity warning systems that warn of a dangerous flight condition are known. Examples of such systems are disclosed in U.S. Pat. Nos. 3,934,221; 3,934,222; 3,944,968; 3,946,358 and 3,958,218, assigned to the assignee of the present invention. All of these systems monitor the radio altitude and the radio altitude closure rate, and generate a warning if the rate of closure rate is excessive for the altitude at which the aircraft is flying.
While these systems do provide a way to warn the pilot of a hazardous condition resulting from an excessive closure rate with terrain, these systems are designed for use in transport aircraft, and not for use in highly maneuverable, hlgh performance tactical aircraft such as fighter or attack aircraft whose flight and operational characteristics are substantially different than those of transport aircraft. Consequently, the systems designed for transport aircraft can provide false warnings during certain normal operational conditions of a tactical aircraft, and provide no warning or an inadequate warning during other flight conditions